Because of the high speed and insufficient stopping distance, a sudden obstacle will force the vehicle to perform a lane change maneuver to avoid a crash or rear-end collision. A vehicle yaw following control system was designed in this paper to prevent vehicles from spinning and drifting out on high speed obstacle avoidance under emergency. However, yaw following control system, in some situation, may not react properly to, or even deteriorate on-road rollover events. Four-wheel steering control system can reduce the excessive yaw movement due to yaw following control system. An integration control system, including yaw following control system and four-wheel steering control system was presented and discussed. With this improved control system, the vehicle lateral stability can be improved on high speed obstacle avoidance.